The Influence of Viscosity and Magnetic Shear on Rayleigh-Taylor Modes of Plasmas

F. T. GRATTON; A. G. GONZÁLEZ

PLASMA PHYSICS AND CONTROLLED FUSION

Pergamon Press

Año: 1986 vol. 28 p. 1807 - 1821

0741-3335

The equations of gravitational modes of stratified. incompressible and ideally conducting fluids. with a viscous tensor in a sheared magnetic field are given. Boundary conditions at fluid discontinuities are derived. Properties of the frequency spectrum are obtained from variational principles. A detailed description of the modes and the Rayleigh-Taylor instability is given for a plasma-vacuum interface. with different magnetic fields on each side, in three cases: isotropic viscous properties. $nu_c>>omega_ci$ $ (omega_ci$, ion cyclotron frequency: $nu_c$ ion collision frequency) and non isotropic viscous properties in the limit $omega_ci>>nu_c$ for k || Bo. which is dominated by dissipative forces and for k perpendicular to Bo. which is governed by gyroscopic forces. Applications of the theory to accelerated plasmas are discussed.